This disclosure relates in general to weather forecasting and, but not by way of limitation, to weather nowcasting by estimating storm motion amongst other things.
The prediction of thunderstorms has been an active and flourishing modern discipline, especially due to the advent of various new technologies including the scanning Doppler weather radar. Conventional meteorological radars provide coverage over long ranges, often on the order of hundreds of kilometers. A general schematic of how such conventional radar systems function is provided in FIG. 1. In this illustration, a radar is disposed at the peak of a raised geographical feature such as a hill or mountain 104. The radar generates an electromagnetic beam 108 that disperses approximately linearly with distance, with the drawing showing how the width of the beam 108 thus increases with distance from the radar. Various examples of weather patterns 116 that might exist and which the system 100 attempts to sample are shown in different positions above the surface 112 of the Earth.
The maximum range of weather radar is usually more than 150 km, while the minimum resolved scale can be 100 to 200 m. The radar observations can be updated in a few minutes. Weather radar has become one of the primary tools for monitoring and forecasting the severe storms that may extend tens to hundreds of kilometers, yet whose scale is still relatively small compared to the synoptic scale of the earth. Many high impact and severe weather phenomena are the meso-scale or the storm-scale systems, having the lifetime from a few tens of minutes to a few hours. So the very short term forecasting of thunderstorms is particularly important to various end users, such as the airport transportation, the highway traffic, the construction industry, the outdoor sporting and entertainment, the public safety management, resource (e.g., agriculture and forest) protection and management. The forecast of such type is termed as the nowcasting, which can be defined as the forecasting of thunderstorms for a very short time periods that are less than a few hours, for example, up to twelve hours.
Many systems predict thunderstorms in the short term using tracking and extrapolation of radar echoes. Some techniques track storms using distributed “motion-field” based storm trackers, another is the “centroid” storm cell tracker. Beyond these techniques, many statistical and numerical models have been used. Despite the litany of research in this area, there remains a need in the art for improved nowcasting techniques.